I propose that MICE enable BGP ADD-PATH capability (RFC 7911) on
the route servers (in TX mode only). This is negotiated BGP
capability, so we do not need any per-participant setting for it.
ADD-PATH is useful if the best path route is being filtered but
another route would not be. We discussed adding this at a UG
meeting years ago.
There are other IXPs that have this enabled. For example, this one: https://www.bcix.de/ixp/content/0/route-servers
In terms of timeline, I propose something like this:
The actual change looks like this for the RS1-only piece, and then the conditional would be removed when we want to deploy to RS2:
---
a/roles/ixpmanager/files/mice/api/v4/router/server/bird2/neighbors.foil.php
+++
b/roles/ixpmanager/files/mice/api/v4/router/server/bird2/neighbors.foil.php
@@ -315,6 +315,9 @@ protocol bgp pb_<?= $int['fvliid']
?>_as<?= $int['autsys'] ?> from tb_rsclient {
import filter f_import_as<?= $int['autsys']
?>;
table t_<?= $int['fvliid'] ?>_as<?=
$int['autsys'] ?>;
export filter f_export_as<?= $int['autsys']
?>;
+<?php if( $t->router->router_id == "206.108.255.1" ):
?>
+ add paths tx;
+<?php endif; ?>
};
<?php if( $int['bgpmd5secret'] &&
!$t->router->skip_md5 ): ?>
password "<?= $int['bgpmd5secret'] ?>";
-- Richard